Apparatus for Simultaneous Size-Differentiated Sampling of Optical and Suboptical Aerosols: Application to Analysis of Nitrates and Sulfates

In recent years, the EPA has moved toward a risk assessment/risk reduction framework for making regulatory decisions. The Agency has taken a number of steps to assure the quality and consistency of the risk assessment component of those decisions. The first, and perhaps most important of these steps, is the development of Agency-wide risk assessment guidelines. Five guidelines have been published. They are: carcinogenicity, mutagenicity, developmental toxicity, chemical mixtures, and exposure. The provisions of the five guidelines are discussed in the context of the four components of risk assessment. Other activities designed to assure quality and consistency in risk assessments, reduce uncertainty in risk assessment, ensure a more efficient information exchange about risk and risk assessment, and develop the appropriate oversight mechanisms are also discussed. These include additional guidelines, the Risk Assessment Forum, risk assessment research, the Integrated Risk Information System, the Hazard Assessment Notification System, and the Risk Assessment Council.     

Legislating risk: the USA struggles to reform its policies for the assessment and management of risk

This paper focuses on recent efforts in the United States to improve the federal government's approach to regulating risk, with particular emphasis on legislation introduced in the Congress of the United States that was designed to reform and standardize risk assessment and risk management practices at the United States Environmental Protection Agency (EPA) and other federal agencies with responsibility for health, safety, and environmental regulation. After reviewing the key provisions of the legislation and the potential impact of those provisions on EPA's risk-related activities, the paper suggests certain fundamental principles that should guide the debate on reform of policies and procedures associated with risk.     

Engineering Bulletins: Aids to the Development of Remedial Alternatives

An overview of activities of the Risk Reduction Engineering Laboratory in response to the Environmental Protection Agency’s Treatability Initiative are described and a summary of the information in the first ten Engineering Bulletins, which are a component of the initiative, is provided.     

Designing a Low-Cost Pollution Prevention Plan to Pay Off at the University of Houston

Abstract

The University of Houston is located just south of downtown Houston, TX. Many different chemical substances are used in scientific research and teaching activities throughout the campus. These activities generate a significant amount of waste materials that must be discarded as regulated hazardous waste per U.S. Environmental Protection Agency (EPA) rules. The Texas Commission on Environmental Quality (TCEQ) is the state regulatory agency that has enforcement authority for EPA hazardous waste rules in Texas. Currently, the University is classified as a large quantity generator and generates >1000 kg per month of hazardous waste. In addition, the University has experienced a major surge in research activities during the past several years, and overall the quantity of the hazardous waste generated has increased. The TCEQ requires large quantity generators to prepare a 5-yr Pollution Prevention (P2) Plan, which describes efforts to eliminate or minimize the amount of hazardous waste generated. This paper addresses the design and development of a low-cost P2 plan with minimal implementation obstacles and strong payoff potentials for the University. The projects identified can be implemented with existing University staff resources. This benefits the University by enhancing its environmental compliance efforts, and the disposal cost savings can be used for other purposes. Other educational institutions may benefit by undertaking a similar process.     

Designing a low-cost pollution prevention plan to pay off at the University of Houston

The University of Houston is located just south of downtown Houston, TX. Many different chemical substances are used in scientific research and teaching activities throughout the campus. These activities generate a significant amount of waste materials that must be discarded as regulated hazardous waste per U.S. Environmental Protection Agency (EPA) rules. The Texas Commission on Environmental Quality (TCEQ) is the state regulatory agency that has enforcement authority for EPA hazardous waste rules in Texas. Currently, the University is classified as a large quantity generator and generates >1000 kg per month of hazardous waste. In addition, the University has experienced a major surge in research activities during the past several years, and overall the quantity of the hazardous waste generated has increased. The TCEQ requires large quantity generators to prepare a 5-yr Pollution Prevention (P2) Plan, which describes efforts to eliminate or minimize the amount of hazardous waste generated. This paper addresses the design and development of a low-cost P2 plan with minimal implementation obstacles and strong payoff potentials for the University. The projects identified can be implemented with existing University staff resources. This benefits the University by enhancing its environmental compliance efforts, and the disposal cost savings can be used for other purposes. Other educational institutions may benefit by undertaking a similar process.     

The "Least Favored Method"—A Primer on the RCRA Land Disposal Regulations

In May of 1990 the U.S. Environmental Protection Agency (EPA) completed a four year long series of rulemakings on land disposal of over. 450 hazardous wastes regulated under the Resource Conservation and Recovery Act (RCRA). The new regulations stipulate that hazardous wastes may not be disposed of on land—if at all—unless they are first treated in a prescribed manner. The Land Disposal Regulations (LDRs) will change disposal requirements for approximately 41 million tons of hazardous waste annually, at a cost to the regulated community of over a billion dollars. Despite EPA’s efforts to educate industry, the LDRs remain a source of confusion for many. This article is intended to clear up at least some of the confusion by providing an overview of the regulations and the decision-making processes which occurred during the four years of EPA rulemakings and, more recently, in the courts.     

Highlights of the Second International Conference on Managing Hazardous Air Pollutants

As the time approaches for the U.S. Environmental Protection Agency (EPA) to evaluate whether risks from electric utility trace substance emissions are of concern, attention is focused on research to clarify the many issues surrounding this topic. Accordingly, more than 230 representatives of industry, government, international research and academic institutions, equipment manufacturers, and engineering service firms attended the Second International Conference on Managing Hazardous Air Pollutants, which was held in Washington, D.C., on July 13–15,1993. Sponsored by the Electric Power Research Institute (EPRI) in cooperation with the EPA, U.S. Department of Energy (DOE), PowerGen, Coal Research Division of the International Energy Agency, and Canadian Electrical Association, the conference featured more than 50 presentations that both asked and answered questions about utility emission sources, the atmospheric fate of emitted substances, health and environmental studies, risk assessment, and control technologies. The diversity of the audience produced a stimulating exchange of findings, interpretations, and assessments of remaining uncertainties. This exchange provided valuable direction for ongoing research activities worldwide.     

Overview and Update of the Superfund Innovative Technology Evaluation (site) Demonstration Program

The Superfund Innovative Technology Evaluation (SITE) Program is now in its sixth year of demonstrating technologies applicable to Superfund sites. The SITE Program, conducted by the U.S. Environmental Protection Agency’s Risk Reduction Engineering Laboratory, is intended to accelerate the use of new and innovative treatment processes as well as evaluate innovative measurement and monitoring techniques. Within the SITE Program, the Demonstration Program and the Emerging Technologies Program are responsible for innovative/ alternative waste treatment technology development. Separate and parallel activities are progressing for development and evaluation of measuring and monitoring technologies as well as technology transfer operations.     

Federal Regulations for New Source Performance Standards

Section 111 of the Clean Air Act Amendments of 1970 authorizes the U.S. Environmental Protection Agency (EPA) to impose emission standards (NSPS) on those stationary sources that are determined to be significant contributors to air pollution and that consequently endanger the public health or welfare. In five years EPA promulgated 19 final and 1 proposed NSPS for stationary sources. Section 112 of the Act authorizes EPA to promulgate national emission standards for hazardous air pollutants (NESHAPS). EPA promulgated three final and 1 proposed regulation under Section 112. In addition, EPA promulgated NSPS for three "designated" pollutants from specific sources under Section Hid. EPA’s use of Section 111 and 112 authority provides for a quick response emission control program compared to the relatively slow process of establishing additional ambient air quality standards and having the states adopt implementation plans (Section 109). Three court cases, argued in the U.S. Court of Appeals for the District of Columbia, established basic guidelines for future promulgation of NSPS although certain legal actions are still pending. Proposed amendments to the Clean Air Act would further broaden and strengthen EPA’s direct regulatory authority.     

Reducing the Risks from Radon

The U.S. Environmental Protection Agency estimates that residential radon levels in the United States lead to approximately 13,600 lung cancer deaths per year. To address this problem, the Agency has identified three program initiatives that can provide substantial reductions in the public’s risks: (1) public information activities that urge the public to test for radon and reduce elevated concentrations in existing homes, (2) new construction standards to reduce radon entry, and (3) radon testing and mitigation during real estate transactions. This paper analyzes the costs and risk reductions that could result from the implementation of these major initiatives, showing how all three elements cost-effectively protect the public’s health.     

Assessment of Needs for Technical Information in EPA’s Hazardous and Solid Waste Programs

Headquarters managers and Regional staff in the U.S. Environmental Protection Agency’s hazardous and solid waste programs were surveyed to determine priorities for technical information and guidance among EPA Regional staff, state hazardous waste management staff, EPA contractors, and the regulated community. The survey also examined delivery systems effective for EPA Regional staff. The fifteen highest ranked technical needs for RCRA, Superfund, and UST reflect a pervasive interest in hazardous waste remediation. Top priority technical needs focus on establishing cleanup levels, subsurface fate and transport, field monitoring and quality assurance, remedy selection, and most importantly, which remedies work and which do not in specific situations. Technical needs of non- EPA audiences are quite similar to those for EPA field staff. Preferences for technology transfer delivery systems are generally for conventional distribution methods (such as print materials and workshops) rather than electronic or video media. Regional staff report serious problems in utilizing technology transfer because of time constraints, insufficient knowledge of available products, insufficient travel funds, and limited access to and training on computers.     

Estimating historical landfill quantities to predict methane emissions

There are no observations for methane emissions from landfill waste in Ireland. Methane emissions are imputed from waste data. There are intermittent data on waste sent to landfill. We compare two alternative ways to impute the missing waste “data” and evaluate the impact on methane emissions. We estimate Irish historical landfill quantities from 1960–2008 and Irish methane emissions from 1968–2006. A model is constructed in which waste generation is a function of income, price of waste disposal and, household economies of scale. A transformation ratio of waste to methane is also included in the methane emissions model. Our results contrast significantly with the Irish Environmental Protection Agency’s (EPA) figures due to the differences in the underlying assumptions. The EPA’s waste generation and methane emission figures are larger than our estimates from the early 1990s onwards. Projections of the distance to target show that the EPA overestimates the required policy effort.     

Pilot-Scale Evaluation of an Incinerability Ranking System for Hazardous Organic Compounds

The U.S. Environmental Protection Agency’s (EPA) hazardous waste incinerator performance standards specify a minimum destruction and removal efficiency (DRE) for principal organic hazardous constituents (POHCs) designated in the incinerator waste feed. In the past, selection of appropriate POHCs for incinerator trial burns has been based largely on their heats of combustion. Attempting to improve upon this approach, the University of Dayton Research Institute (UDRI), under contract to the EPA Risk Reduction Engineering Laboratory, has developed a thermal stability-based ranking of compound "incinerability". The subject study was conducted to evaluate the laboratory-developed ranking system in a pilot-scale incinerator.

Mixtures of POHCs, spanning the ranking scale from most- to least-difficult to destroy (Class 1 to Class 7, respectively), were prepared and combined with a clay-based sorbent matrix. These mixtures were then fed into the rotary kiln incineration system at the U.S. EPA Incineration Research Facility (IRF). In a series of five tests, the following conditions were evaluated: baseline/ typical operation; thermal failure (quenching); mixing failure (overcharging); matrix failure (low feed H/CI ratio); and a worst-case combination of the three failure modes.

Under baseline conditions, mixing failure, and matrix failure, kiln-exit DREs for each compound were comparable from test to test. Operating conditions in these 3 modes appeared to be sufficient to effect considerable destruction (greater than 99.99 percent DRE) of all compounds. As a result, separation of the highest-ranked POHCs from the lowest-ranked POHCs according to observed DRE was not possible; a correlation between POHC ranking and DRE could not be confirmed.

A correlation between predicted and observed incinerability was more evident for the thermal failure and worst-case conditions. Kiln-exit DREs for the four POHCs predicted to be most stable (those in Classes 1 and 2) ranged from 99% to 99.99% under these conditions, and were generally lower than DREs for the POHCs predicted to be more easily destroyed. Statistically significant correlations above the 99 percent and 93 percent confidence intervals were identified for the thermal-failure and worst-case tests, respectively.     

Estimating Costs of Flue Gas Desulfurization Systems for Utility Boilers

In September 1973, PEDCo-Environmental Specialists was awarded a study by the U. S. Environmental Protection Agency to evaluate the cost of controlling sulfur dioxide and particulate emissions from selected utility boilers. Since that time, PEDCo has conducted additional studies for the U. S. EPA, state and local control agencies, and private industry on the costs of control technology and the reliability of sulfur dioxide control systems. Current work includes determining the feasibility and environmental impact of converting selected utility boilers to coal-firing to conserve the nation’s gas and oil supplies. This paper presents an overview of the status and costs of flue gas desulfurization (FGD) systems, and the factors relating to the variability in costs. It is based in part upon work performed in developing detailed FGD cost estimating manuals for EPA.     

Greenhouse gas emissions from waste management--assessment of quantification methods

Of the many sources of urban greenhouse gas (GHG) emissions, solid waste is the only one for which management decisions are undertaken primarily by municipal governments themselves and is hence often the largest component of cities' corporate inventories. It is essential that decision-makers select an appropriate quantification methodology and have an appreciation of methodological strengths and shortcomings. This work compares four different waste emissions quantification methods, including Intergovernmental Panel on Climate Change (IPCC) 1996 guidelines, IPCC 2006 guidelines, U.S. Environmental Protection Agency (EPA) Waste Reduction Model (WARM), and the Federation of Canadian Municipalities-Partners for Climate Protection (FCM-PCP) quantification tool. Waste disposal data for the greater Toronto area (GTA) in 2005 are used for all methodologies; treatment options (including landfill, incineration, compost, and anaerobic digestion) are examined where available in methodologies. Landfill was shown to be the greatest source of GHG emissions, contributing more than three-quarters of total emissions associated with waste management. Results from the different landfill gas (LFG) quantification approaches ranged from an emissions source of 557 kt carbon dioxide equivalents (CO2e) (FCM-PCP) to a carbon sink of -53 kt CO2e (EPA WARM). Similar values were obtained between IPCC approaches. The IPCC 2006 method was found to be more appropriate for inventorying applications because it uses a waste-in-place (WIP) approach, rather than a methane commitment (MC) approach, despite perceived onerous data requirements for WIP. MC approaches were found to be useful from a planning standpoint; however, uncertainty associated with their projections of future parameter values limits their applicability for GHG inventorying. MC and WIP methods provided similar results in this case study; however, this is case specific because of similarity in assumptions of present and future landfill parameters and quantities of annual waste deposited in recent years being relatively consistent.     

Use of Probabilistic Methods to Understand the Conservatism in California’s Approach to Assessing Health Risks Posed by Air Contaminants

Many state and federal agencies have prepared risk assessment guidelines, which describe methods for quantifying health risks associated with exposure to vapors and particulates emitted from point and area sources (e.g., California Air Pollution Control Officers Association [CAPCOA] under the Air Toxics “Hot Spots” Act [Assembly Bill 2588] and the U.S. Environmental Protection Agency [EPA] under the Clean Air Act). In general, these guidelines recommend or require the use of upper bound “point” estimates for numerous exposure parameters. This methodology yields a single risk estimate, which is intended not to underestimate the true risk and may significantly overstate it. This paper describes a risk assessment of a facility’s airborne emissions using a probabilistic approach, which presents a range and distribution of risk estimates rather than a single point estimate. The health risks to residents living near a food processing facility, as estimated using techniques recommended by California AB2588, are compared to the results of a probabilistic analysis. Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were identified as the emitted chemicals of concern. The point estimate method recommended by CAPCOA resulted in estimates that were greater than the 99.99th percentile risk predicted by the probabilistic analysis. As shown in other assessments of persistent airborne chemicals, secondary or indirect exposure pathways (i.e., ingestion of beef, ingestion of cow’s milk, and ingestion of mother’s milk) rather than inhalation, were the greatest contributors to risk. In this analysis, the probability distributions for the cancer potency factor and ingestion of cow’s milk had the largest impact on the results of the 33 exposure factors considered.     

Stack Dust Sampling: in-Stack Filter or E.P.A. Train

The Environmental Protection Agency has recommended or specified methods for the measurement of participate concentrations in flue gases. The EPA Train for this measurement originally comprised two segments: the front half and the impinger train downstream from the filter proper. This review examines the controversial areas implicit in the use of this EPA Train or the revised EPA train which eliminates the impinger train.     

Risk of polycyclic aromatic hydrocarbon (PAH) exposure from ingested food: the Azerbaijan case study

Risks due to polycyclic aromatic hydrocarbons (PAHs) exposure from food consumption for the population of Azerbaijan were determined using deterministic and probabilistic methods. The guidelines and methods described and presented in the United States Environmental Protection Agency (U.S. EPA) Risk Assessment Guidance for Superfund (RAGS) Part A was used in performing the risk assessments. The current study utilized concentration data from different sources representing international studies performed over the past decade to determine those food products that contribute the most exposure to PAHs through ingestion for the Azeri population. Due to lack of concentration data from middle-Eastern countries, only European countries were considered and used for this analysis. Using the benzo[a]pyrene (BaP) toxicity equivalency factors (TEFs) to adjust the concentrations of the individual PAH compounds to BaP equivalent concentrations, risk analyses were performed. Deterministic risk estimates fell within probabilistic risk estimates. Child risks were consistently four to seven times higher in magnitude than adult risks. Risk potentials determined for the food exposure pathway were also determined to be up to ten times higher in magnitude than risks determined from exposures due to other pathways such as soil contamination. It was observed that three major factors contributed to the variability in the assessment results, which were child and adult body weights, consumption rates of the different food groups, and the variances of the input data. The most prevalent pathways of PAH exposure from the dietary patterns of the Azerbaijani population were determined to be from bread and bakery products, milk and dairy products, and egg products.     

A Comparison of Two Techniques for the Collection and Analysis of Polynuclear Aromatic Compounds in Ambient Air

A demonstration of the GHEMFIX solidification/stabilization process was conducted under the United States Environmental Protection Agency’s (EPA) Superfund Innovative Technology Evaluation (SITE) program. The demonstration was conducted in March 1989, at the Portable Equipment Salvage Company (PESC) uncontrolled hazardous waste site in Clackamas, Oregon. Waste containing lead, copper, and polychlorinated biphenyls (PCBs) from four different areas of the site were treated. Results showed substantial reduction of leachable lead and copper between the untreated waste and treated waste utilizing the EPA Toxicity Characteristics Leaching Procedure (TCLP) test. The effectiveness of this process for immobilizing PCBs could not be determined since the raw waste did not leach PCBs at high concentrations, utilizing the TCLP test. Data from other leaching tests for lead and copper would need to be utilized as input into a site specific groundwater model to determine whether solidification/stabilization would be an acceptable remedy for the site. Physical testing results indicated durability in exposed conditions.